Drill steel retainer



July 22, 1952 FEUCH-r 2,604,328

DRILL STEEL RETAINER Filed July 2'7, 1948 l8 l6 2| 26 25 22 27 I4 FIG. I

ALBERT FEUCHT F 3 INVENTOR.

ATTORNEY Patented July 22, 1952 DRILL STEEL RETAINER Albert Feucht, Cleveland, Ohio, assignor to Le Roi Company, Milwaukee, Wis., a corporation of Wisconsin Application July 27, 1948, Serial No. 40,840

This invention relates broadly to rock drills of the percussive type, but more particularly to improvements in drill steel retainer therefor.

One object of this invention is to produce a releasable drill steel retainer which is simple in design, economic in manufacture, and susceptible of ready manipulation.

Another object of this invention is to provide a drill steel retainer with cushioning means for absorbing the blows of the drill steel against the retainer.

Another object of this invention is to provide a drill steel retainer with simple and efficient looking means for positively locking the retainer into operative position, which means enables easy manipulation of the retainer independently of the cushioning means, thereby preventing accidental movement of the retainer into inoperative position by virtue of the drill steel blows imparted thereto.

Another object of this invention is to produce a drill steel retainer constructed and arranged in a manner preventing wear of integral parts of the rock drill with which the retainer is associated.

These objects are accomplished by a construction free of complications, and by an arrangement of parts resulting in a compact unit which is strong, durable and eflicient.

In the drawings which illustrate a preferred embodiment of the invention:

Figure 1 is a side longitudinal view of the front end of a rock drill having the invention applied thereto.

Figure 2 is a view similar to Figure 1 but showing the retainer in a different position.

Figure 3 is a front longitudinal view of the retainer looking in the direction of the arrow 3 in Figure 1.

Figure 4 is an end view of the retainer in the position shown in Figure 1.

Figure 5 is an end view of the retainer in the position shown in Figure 2.

Referring to the drawings in which like symbols designate corresponding parts throughout the several views, In represents the front housing of a rock drill which is adapted to slidably receive the shank of a drill steel l2 having a collar [4 formed integrally therewith and engageable with the front end of the housing II] for limiting the penetration of the drill steel shank into the housing.

Forward its front end, the housing In is provided with two diametrically opposed trunnions 16 formed integrally with the housing and ex- 3 Claims. (01. 27919.1)

tending laterally therefrom in opposite directions; On each trunnion [6, there is rotatably mounted a substantially U-shaped cap l8 which fits over more than one-half of the trunnion, thereby enabling removal of the cap from the trunnion only axially relative to the latter. The side arms of the cap [8 are each ended by a per fectly flat section forming together a flat seat 20 which extends laterally from the trunnion in opposite directions and has intermediate its ends a portion of the trunnion extending therebeyond. Extending perpendicularly from the seat 20, each side arm of the cap I8 has a threaded bore 2! adapted to receive the threaded end of a bolt 22 which extends therefrom toward the front end of the housing l0.

Straddling the front housing [0, there are the two side arms 23 of a substantially U-shaped drill steel retaining member 24. Each side arm 23 has its free end enlarged into a substantially rectangular head 25 normally adapted to rest against the cap seat 20 and having its central portion immediately below the trunnion sufiiciently relieved or concaved to prevent engagement of the head with the trunnion. Each head 25 is also provided with two apertures 26 through which the bolts 22 extend and form sliding guides for the retaining member 24. The sliding movement of the retainer on the guides 22 is checked or cushioned by a compression spring 21 mounted on the bolts 22 and through which the heads 25 are normally maintained against the seats 26. Extending radially from the center axis of each trunnion l6, there'is a bore 28 which leads from the head 25 part way into the arm 23, within which bore is slidably mounted a plunger or detent 29 constantly forced into engagement with the trunnion through a compression spring 39. To look the retaining member in operative position, the trunnion I6 is provided with a notch 31 adapted to receive the end of the detent 29.

The closed end of the retaining member 24 is formed with a yoke 32 adapted to partly surround the drill steel l2 ahead of the collar I4 and normally engageable with the collar to prevent removal of the drill steel from the housing Hi.

In the operation of the device, when the retainer 24 is positioned as shown in Figures 1 and 4, that is, in operative position, the removal of the drill steel I 2 from the housing I0 is prevented by the drill steel collar l4 engaging the yoke 32. When the collar [4 accidentally strikes the yoke 32, the compression springs 21 act as a cushioning medium to absorb the shocks, which would otherwise be transmitted from the yoke 32 to the trunnion [6 with deleterious effect. During this shock absorption, it will be noticed that the caps 18 remain in engagement with the trunnion 16 without any relative movement therebetween, and since the arms 23 of the retaining member 24 do not engage the trunnions, the impacts to which the yoke 32 may be subjected will not in any way affect the trunnion, an advantage which has not before been realized with tool retainers of a similar type.

While in operative position, the detent 29 nest.- ed within the notch 3| will positively maintain. the retaining member 24 against accidental pivotal movement into open position. Since the operation of this locking device is not dependent upon the compression springs 21, it will be understood that when the retainer 24 is subjected to the accidental impacts of the collar [4, the resulting slidable movement or reciprocation of the retainer will not tend to release the locking device and enable movement of the retainer into open position, a condition which has been found to exist in other tool retainers of a similar type. Furthermore, since the locking device is depend-- ent for its efficient operation primarily on the small compression springs 39, it can be so constructed that it is perfectly dependable for holding the retainer in operative position and yet be readily manipulated or shifted into operative position as shown in Figures 2 and 5, Without having to overcome the effort of the compression springs 21.

When the retainer is moved from one position to another, the entire assembly pivots as a unit on the trunnions Is. In this instance, the detent 29 pressed against the trunnions 16 by the small compression springs 30 will be suificient to frictionally holdthe retainer in open position and enable removal of the drill steel.

From the foregoing description, it will be understood that the only wear to which the trunnions [6 are subjected is occasioned by the pivotal movement of the retainer assembly from one to another position, and that the impacts to which the yoke 32 is subjected do not cause the wear of the trunnion. The reciprocatory movement of the retaining member is. checked or cushioned in onedirection by the compression springs 21' and limited intheother direction by the engagement of the heads 25 with the seats 20- of the caps I8, both heads and seats having large interengaging faces especially treated to stand the impacts to which they are subjected. It will also be understood that the locking device is entirely independent of the cushioning deviceandi that the entire construction is of simple and compact design having many advantages never before encountered indrill steel retainers of this type.

I claim:

1. In a'percussive tool, the combination of a front head adapted to receive the collared shank of a drill steel and having trunnions extending laterally therefrom on opposite sides thereof, a drill steel retainer comprising a yoke, caps pivotally mounted on said trunnions, means for yieldably connecting the free ends of the side arms of said yoke to said caps in spaced relation with said trunnions, and locking means between said side arms and trunnions including spring pressed detents within said side arms operatively engaging said trunnions.

2. In. a percussive tool, the combination of a front head-adapted to receive the collared shank of a drill steel and having trunnions extending laterally therefrom on opposite sides thereof, a drill steel retainer comprising a yoke, caps pivotally mounted on said trunnions, a seat on each of said caps, the free end of each side arm of said yoke being adapted, to rest against said seat in spaced relation with said trunnions, spring means for yieldably connecting said side arms to said caps with said free ends normally resting against said seats, and locking means between said side arms and trunnions including spring pressed detents within said side arms operatively engaging said trunnions.

3. In a percussive tool, the. combination of a front head adapted to receive the collared shank of a drill steel and having trunnions extending laterally therefrom on opposite sides thereof, a drill steel retainer comprising a yoke, caps pivotally mounted on said trunnions, a seat on each of said caps extending laterally on opposite sides of the trunnion, the free end of each side arm of said yoke being adapted to rest against said seat in spaced relation with said trunnions, spring means carried by said caps for yieldably connecting said side arms to said caps with said free ends normally resting against said seats, and means within said side arms frictionally engaging said trunnions for restraining the pivotal movement of said retainer on said trunnions.

ALBERT FEUCHT.

REFERENCES CITED The following references are of record in the 1c of this patent:

UNITED STATES PATENTS 

